British painter and printmaker Bridget Riley was, along with Victor Vasarely, one of the major proponents of Op art during the 1960s. Riley studied in London at Goldsmiths College (1949-52) and the Royal College of Art (1952-5). Her interest in optical effects initially led her to the Neo-Impressionist style of pointillism, and later to color field painting (1959-61). When she took up Op art in the early 1960s she first limited her palette to black and white, only turning to color in 1966.

One of Riley's paintings was used on the cover of the catalogue for the first survey of the Op art movement, the 1965 exhibition "The Responsive Eye" at the Museum of Modern Art, New York. In 1968 she was awarded the international painting prize at the Venice Biennale.

Riley typically uses studio assistants to complete her paintings, supplying them with scale drawings in graphite and gouache that deliniate with mathematical precision the colors and patterns to be repeated across the canvas. The large-edition screenprint "Untitled (Wave)" from 1975 is closer in character to these working drawings than Riley's mezmerizing, undulating canvases, its small snippet of pattern and color only hinting at the effect to be gained through repetition.

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